1/3x+y=-1
4x-3y=18
2007-11-04 14:32:10 · 7 answers · asked by Jamie M 1 in Science & Mathematics ➔ Mathematics
Reading as:-
(1/3) x + y = - 1
y = - 1 - (1/3) x
4x - 3 [ - 1 - (1/3)x ] = 18
4x + 3 + x = 18
5x = 15
x = 3
1 + y = - 1
y = - 2
x = 3 , y = - 2
2007-11-04 20:16:28 · answer #1 · answered by Como 7 · 0⤊ 1⤋
y = -1 - 1/3x
Substitute that in the second equation:
4x - 3(-1 - 1/3x) = 18
4x + 3 + x = 18
5x = 15
x = 3
Now 3y = 4*3 - 18
3y = -6 > y = -2
2007-11-04 14:37:35 · answer #2 · answered by Aeons 2 · 0⤊ 0⤋
y = -1 - 1/3x
4x - 3(-1 - 1/3x) = 18
4x + 3 + x = 18
5x + 3 = 18
5x = 15
x = 3
4(3) - 3y = 18
12 - 3y = 18
-3y = 6
y = -2
2007-11-04 14:41:23 · answer #3 · answered by Anonymous · 0⤊ 0⤋
y = -1/3x -1
4x -3(-1/3x - 1) = 18
4x + x + 3 = 18
5x = 15
x = 5
y = -1/3(5) - 1
y = -5/3 - 1
y = -5/3 - 3/3
y = -8/3
y = -2 and 2/3
2007-11-04 14:37:04 · answer #4 · answered by Ms. Exxclusive 5 · 0⤊ 0⤋
first you take either of the equations and get them so that you have one variable alone on one side
x/3 + y = -1
y = -x/3 - 1
then you take the value of that variable and substitute it in for that variable
4x - 3y = 18
4x - 3(-x/3 - 1) = 18
use the distributive property if necessary, which it is in this case
4x + x + 3 = 18
combine like terms
5x +3 = 18
again, get the variable on one side
5x = 15
and get the variable alone
x = 3
2007-11-04 14:41:06 · answer #5 · answered by silentiumcide 1 · 0⤊ 0⤋
y = -2 ANSWER for value of y
x = 3 ANSWER for value of x
1/3x + y = -1 MULTIPLY both sides by 3
x + 3y = -3 SUBTRACT 3y from both sides
x = -3y - 3
SUBSTITUTE x = -3y - 3 into the second equation
4(-3y - 3) - 3y = 18
-12y - 12 - 3y = 18
-15y - 12 = 18 ADD 12 to both sides
-15y = 30 DIVIDE both sides by -15
y = -(30/15)
y = -2 ANSWER for value of y
SUBSTITUTE y = -2 into the first equation and solve for x
1/3x + y = -1
1/3x - 2 = -1 ADD 2 to both sides
1/3x = 1 MULTIPLY both sides by 3
x = 3 ANSWER for value of x
CHECK by putting x = 3 into the second equation and solve for y
4x - 3y = 18
4 (3) - 3y = 18
12 - 3y = 18 SUBTRACT 12 from both sides
-3y = 6 DIVIDE both sides by -3
y = -2 (it checks out with the previous value of y)
2007-11-04 14:45:07 · answer #6 · answered by Anonymous · 0⤊ 0⤋
okay im doing this stuff in class so ill work it out for ya i love algebra!
1. y=1/3x-1
2.y=-4x+18 divided by -3(put a fraction bar underneath -4x+18 and then under the fraction bar -3)
2007-11-04 14:39:25 · answer #7 · answered by TheCuriousOne 2 · 0⤊ 0⤋